Synlett 2015; 26(17): 2462-2466
DOI: 10.1055/s-0035-1560205
letter
© Georg Thieme Verlag Stuttgart · New York

A Facile, Convenient, and Green Route to (E)-Propenylbenzene Flavors and Fragrances by Alkene Isomerization

Casey R. Larsen
,
Erik R. Paulson
,
Gulin Erdogan
,
Douglas B. Grotjahn*
Weitere Informationen

Publikationsverlauf

Received: 30. März 2015

Accepted after revision: 30. Juli 2015

Publikationsdatum:
08. September 2015 (online)


This article is dedicated to Peter Vollhardt with gratitude for his creative, scientific, and mentoring influences, and his love of one-pot reactions

Abstract

(E)-Propenylbenzene flavors and fragrances can be made and isolated in high yield and selectivity by using bifunctional catalyst 1, and the heterogenized analogues. Multigram-scale reactions can be performed neat and the products isolated either by distillation, using homogeneous catalyst 1 (0.1–0.5 mol%, r.t., 10–45 min), or by decantation from heterogeneous catalysts PS-1 or PSL-1 (0.5 mol%, 70 °C, 24 h; catalyst separation and re-use shown for 3–4 cycles; 10 cycles using distilled eugenol feedstock). Both purified starting materials and essential oil feedstocks could be used. Z Isomers were present at very low levels (from 0.4% to less than 0.1%) in the products.

Supporting Information